Object Oriented Finite Element Analysis for Structural Optimization using p-Elements

The optimization of continuous structures requires careful attention to discretization errors. Compared to ordinary low order formulation (h-elements) in conjunction with an adaptive mesh refinement in each optimization step, the use of high order finite elements (so called p-elements) has several advantages. However, compared to the h-method a higher order finite element analysis program poses higher demands from a software engineering point of view. In this article the basics of an object oriented higher order finite element system especially tailored to the use in structural optimization is presented. Besides the design of the system, aspects related to the employed implementation language Java are discussed

Potentielle Auswirkung der Genese der Schwerhörigkeit aud die subjektiv empfundene Lebensqualität

Die Pilotstudie der Hals-Nasen und Ohrenklinik der Universität Marburg hatte das Ziel den Einfluss der Ursache der Schwerhörigkeit auf die subjektiv empfundene Lebensqualität der Patienten genauer zu beleuchten. Dazu wurden 100 Patienten anhand der objektiven klinischen Daten in vier Gruppen unterteilt ( Hörsturz, chronische Otitis media, M Menière und Otosklerose).Anhand der Königsteiner Richtlinien wurde der objektive Schweregrad bestimmt. Zusätzlich wurden die Patienten mit dem neu entwickelten Fragebogen zur Erfassung der Lebensqualität (FELAS) bezüglich der subjektiven Lebensqualität in den Rubriken Kommunikation, Aktivitätsminderung und emotionale Einbußen eruiert. In einem ersten Schritt wurden die Gruppen unterschiedlicher Genese mittels der multifaktoriellen Varianzanalsyse auf Unterschiede zwischen den Gruppen bezüglich der Lebensqualität untersucht. Dabei ließen sich keine signifikanten Unterschiede feststellen. Die Ursache der Schwerhörigkeit scheint demnach keinen Einfluss auf die Lebensqualität schwerhöriger Patienten zu haben. Zur Klärung der Frage, ob die klinischen Einteilungen mit der subjektiven Einschätzung korrelieren wurde eine Rang-Korrelation nach Spearman/Brown durchgeführt. Die dabei berechneten Korrelationen lassen eine Einschätzung der Lebensqualität auf Grund der objektiven Daten der klinischen Einteilung nicht zu

Leistungsbeurteilung und Geschlechtsdiskriminierung

In Zeiten einer zunehmenden Bedeutung betrieblicher Personalbeurteilung und leistungsabhängiger Entlohnung stellt sich die Frage, inwieweit Instrumente der Leistungsbeurteilung Geschlechtsdiskriminierungen in personal- und führungspolitischen Entscheidungen stützen oder sogar verdecken können. Der Artikel wirft einen kritischen Blick auf unser gesellschaftlich verankertes Verständnis von Leistung, bietet eine dazu differierende Beschreibung der Leistungsbeurteilung als sozialen Prozess an und skizziert auf dieser Basis Quellen der Geschlechtsdiskriminierung. Abschließend werden Gestaltungshinweise für Instrumente der Leistungsbeurteilung gegeben.The influence of performance appraisal and performance-based payment models is rising. Therefore, it should be considered if and possibly how performance appraisal instruments contain or produce sources of sex discrimination. The article undertakes a critical review of what we usually call "performance", provides a description of performance appraisal as a social process and explains some crucial sources of discrimination within. Finally, directions for the development and evaluation of performance appraisal instruments are suggested

Free vibration analysis of curved Bernoulli-Euler beam using isogeometric approach

Isogeometric analysis (IGA) is based on a concept that uses the same base functions for representing both the model geometry and the solution space. The most common base functions used in the IGA are NURBS (Non-Uniform Rational B-Splines) functions for their capability to analytically represent various geometries. In this paper, the IGA is applied in the free vibration analysis of rotation-free plane curved Bernoulli-Euler beam. The stiffness and mass matrices have been developed using basic concepts of continuum mechanics and the principle of virtual work. Geometry of the undeformed and deformed beam is defined using convective coordinates and cross section basis vectors. Results of the free vibration analysis for beam with arbitrary curvature are compared with the results obtained from the conventional finite element method (FEM) software. The significant advantages of the IGA approach over the FEM are shown and discussed

Potentielle Auswirkung der Genese der Schwerhörigkeit aud die subjektiv empfundene Lebensqualität

Die Pilotstudie der Hals-Nasen und Ohrenklinik der Universität Marburg hatte das Ziel den Einfluss der Ursache der Schwerhörigkeit auf die subjektiv empfundene Lebensqualität der Patienten genauer zu beleuchten. Dazu wurden 100 Patienten anhand der objektiven klinischen Daten in vier Gruppen unterteilt ( Hörsturz, chronische Otitis media, M Menière und Otosklerose).Anhand der Königsteiner Richtlinien wurde der objektive Schweregrad bestimmt. Zusätzlich wurden die Patienten mit dem neu entwickelten Fragebogen zur Erfassung der Lebensqualität (FELAS) bezüglich der subjektiven Lebensqualität in den Rubriken Kommunikation, Aktivitätsminderung und emotionale Einbußen eruiert. In einem ersten Schritt wurden die Gruppen unterschiedlicher Genese mittels der multifaktoriellen Varianzanalsyse auf Unterschiede zwischen den Gruppen bezüglich der Lebensqualität untersucht. Dabei ließen sich keine signifikanten Unterschiede feststellen. Die Ursache der Schwerhörigkeit scheint demnach keinen Einfluss auf die Lebensqualität schwerhöriger Patienten zu haben. Zur Klärung der Frage, ob die klinischen Einteilungen mit der subjektiven Einschätzung korrelieren wurde eine Rang-Korrelation nach Spearman/Brown durchgeführt. Die dabei berechneten Korrelationen lassen eine Einschätzung der Lebensqualität auf Grund der objektiven Daten der klinischen Einteilung nicht zu

Incremental Urbanism: A study of incremental housing production and the challenge of its inclusion in contemporary planning processes in Mumbai, India

Whilst urbanisation reached an unprecedented dimension, in a not so distant future half of the urban population will live in `informal¿ settlements. Often subsumed under the pejorative term slum, these habitats account for the majority of the future urban growth. Incremental urban development was once accepted as a viable means of addressing housing needs for large parts of the urban population. However, these approaches were largely abandoned in the 1990s in favour of mass housing provided through public private partnerships. While these largely failed in providing the required quantities and produced poor urban spaces, the scale of the phenomenon is such that incremental urban development needs reconsidering. However, in contrast to the well-documented experiences of the 1970s and 1980s, there is a lack of knowledge about the actual functioning of incremental development in contemporary regimes of urbanisation. Adopting an approach informed by French pragmatist sociology (Boltanski and Thévenot 2006), particularly the sociology of convention (Thévenot 1984), this research inquires into the production of slums at two levels: the intricate reality of housing production in Mumbai¿s slums and the contemporary controversies revolving around urban development. Building on fieldwork in a `self-built¿ resettlement colony in Mumbai forty years after it was established, this research examines how incrementally developing settlements are made, maintained, and transformed through everyday practices of local actors. Standing at the crossroads of the market, the political, and the social the so-called contractors are key figures engaged in the processes of construction and house making. As mediators in and of incremental urbanism they produce not only built-up space but also social space. Focusing on contractors as hitherto under-examined figures reveals that self-help housing in Mumbai, in contrast to conventional believes about housing practices of the urban poor, is by and large a professionalised mode of urban production. This research offers a refined account of the intricate reality of housing production and the ambiguous nature of incremental urbanism. Regarding urban planning, this research analyses the on-going revision of the Mumbai Development Plan 2014-2034 and the controversies accompanying it, which brings to the forefront the interplay of powers and arguments that otherwise are disguised in the dispersed and detached everyday making of the city. To better understand the discourse on current planning practices and struggles over conflicting approaches towards slums, this research examines the arguments and legitimization principles that underpin four major positions advocated in the controversies as the `good¿ way to urbanisation. Considering them as equally valid positions allows drawing comparisons between the different conceptualisations of urban planning and development, and the role and legitimacy they confer to modes of incremental urbanism. Reading the two moments in the production of Mumbai¿s slums together sheds light on the challenges to incorporate incremental urbanism into planning processes. It is argued that these challenges lie not solely with the conflicting rationalities ¿ or cosmos ¿ of how to create a just city, which clash in the controversies, but also with the ambiguity of incremental urbanism itself. Both of which contribute to complex processes of invisibilisation, or subalternisation, of incremental urbanism

A FRAMEWORK FOR THE INTERACTIVE VISUALIZATION OF ENGINEERING MODELS

Interactive visualization based on 3D computer graphics nowadays is an indispensable part of any simulation software used in engineering. Nevertheless, the implementation of such visualization software components is often avoided in research projects because it is a challenging and potentially time consuming task. In this contribution, a novel Java framework for the interactive visualization of engineering models is introduced. It supports the task of implementing engineering visualization software by providing adequate program logic as well as high level classes for the visual representation of entities typical for engineering models. The presented framework is built on top of the open source visualization toolkit VTK. In VTK, a visualization model is established by connecting several filter objects in a so called visualization pipeline. Although designing and implementing a good pipeline layout is demanding, VTK does not support the reuse of pipeline layouts directly. Our framework tailors VTK to engineering applications on two levels. On the first level it adds new – engineering model specific – filter classes to VTK. On the second level, ready made pipeline layouts for certain aspects of engineering models are provided. For instance there is a pipeline class for one-dimensional elements like trusses and beams that is capable of showing the elements along with deformations and member forces. In order to facilitate the implementation of a graphical user interface (GUI) for each pipeline class, there exists a reusable Java Swing GUI component that allows the user to configure the appearance of the visualization model. Because of the flexible structure, the framework can be easily adapted and extended to new problem domains. Currently it is used in (i) an object-oriented p-version finite element code for design optimization, (ii) an agent based monitoring system for dam structures and (iii) the simulation of destruction processes by controlled explosives based on multibody dynamics. Application examples from all three domains illustrates that the approach presented is powerful as well as versatile

Object Oriented Finite Element Analysis for Structural Optimization using p-Elements

The optimization of continuous structures requires careful attention to discretization errors. Compared to ordinary low order formulation (h-elements) in conjunction with an adaptive mesh refinement in each optimization step, the use of high order finite elements (so called p-elements) has several advantages. However, compared to the h-method a higher order finite element analysis program poses higher demands from a software engineering point of view. In this article the basics of an object oriented higher order finite element system especially tailored to the use in structural optimization is presented. Besides the design of the system, aspects related to the employed implementation language Java are discussed